Search

The purpose of this paper is to describe the process of building a coherent frame for the identification of local environmental urban vulnerabilities, coping with heat waves' increasing threats, and adopting specific adaptation policies in the Emilia-Romagna region. A microclimate model (ENVI-met) was used to simulate temperature regimes in five areas of Bologna, providing ex ante maps enabling us to locate the most vulnerable areas. Adaptation measures were suggested with the support of WMO Guidance 1234 and included recommendations about the introduction of high-albedo building materials and nature-based solutions. The step-by-step methodology developed, coupling local vulnerabilities with adaptation recommendation, integrates a scientific methodology into a political decision. The results, allowing us to widely represent this city's vulnerability, are considered outstanding with respect to supporting the city's adaptation ambitions and are now part of the running Bologna General Urban Plan (PUG), which regulates building interventions, introducing the obligation for enterprises to respect or ameliorate the microclimate in all the areas in which they intervene. This tool can be replicated and adapted to any municipal area, as it integrates authoritative WMO solutions with accurate microclimate assessment, thus providing locally tailored adaptation interventions. This paper aims to support the vision, shared by both science and policy makers, of transforming cities into widely resilient systems. [ABSTRACT FROM AUTHOR]

Simple Summary: Anthropogenic climate change is one of the greatest threats to biodiversity. Extreme temperature events associated with longer-term climate change are increasing in frequency, duration and intensity. The effects of climatic extremes on ectotherms, such as insects, have been well-studied in recent years. However, the effects of extreme temperatures on other arthropod groups, such as spiders, has received much less attention. Spiders are important organisms as predators in natural and agricultural ecosystems. In this paper, we describe spider responses to extreme temperatures and highlight the most important knowledge gaps that urgently need to be filled to better understand how vulnerable spiders are to climate change and climatic extremes. Unlike insects, traits such as body size and niche breadth may differ markedly in male and female spiders. Therefore, we argue that research needs to address the effects of heat exposure on the physiology, behavior and ecology of male and female spiders across multiple taxa. Observed declines in some terrestrial insects have been widely reported in recent years, with climate change, along with other anthropogenic threats, being implicated. Longer-term data on trends in spider abundance, where available, may also shed possible light on the role of climate change. Climatic extremes, such as heat waves, are increasing in frequency, intensity and duration under anthropogenic climate change. These extreme events pose a great threat to many organisms, and especially ectotherms, which are susceptible to high temperatures. In nature, many ectotherms, such as insects, may seek cooler microclimates and 'ride out´ extreme temperatures, especially when these are transient and unpredictable. However, some ectotherms, such as web-building spiders, may be more prone to heat-related mortality than more motile organisms. Adult females in many spider families are sedentary and build webs in micro-habitats where they spend their entire lives. Under extreme heat, they may be limited in their ability to move vertically or horizontally to find cooler microhabitats. Males, on the other hand, are often nomadic, have broader spatial distributions, and thus might be better able to escape exposure to heat. However, life-history traits in spiders such as the relative body size of males and females and spatial ecology also vary across different taxonomic groups based on their phylogeny. This may make different species or families more or less susceptible to heat waves and exposure to very high temperatures. Selection to extreme temperatures may drive adaptive responses in female physiology, morphology or web site selection in species that build small or exposed webs. Male spiders may be better able to avoid heat-related stress than females by seeking refuge under objects such as bark or rocks with cooler microclimates. Here, we discuss these aspects in detail and propose research focusing on male and female spider behavior and reproduction across different taxa exposed to temperature extremes. [ABSTRACT FROM AUTHOR]